Reductive Activation of Carbon-Fluorine Bonds in Perfluoroalkyl Ligands: An Unexpected Route to the Only Known Tetrafluorobutatriene Transition Metal Complex: Ir(η~5-C_5Me_5)(PMe_3)(2,3-η~2-CF_2=C=C=CF_2)

摘要

Although tetrafluorobutatriene (1) was first prepared more than 40 years ago, only recently has its low-temperature molecular structure been reported, following development of a more efficient synthesis. Originally described as a "treacherously explosive" liquid, even at its melting point of -5 ℃, and more recently shown to decompose slowly even at -80 ℃, it is clearly a highly reactive molecule. However, many unstable or labile organic molecules have been trapped and stabilized via transition metal coordination, and we have extended this series recently to include reactive fluorocarbons such as tetrafluorobenzyne in complexes such as Cp~*Ir(PMe_3)(C_6F_4). Here, we report an in situ synthesis of tetrafluorobutatriene within the coordination sphere of iridium, using a novel route involving the reductive activation of saturated carbon-fluorine bonds.